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157 Cards in this Set
- Front
- Back
What instrument measures the weight of air? |
Barometer |
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What is the standard atmospheric pressure at sea level, measured in inches of mercury? PSI? |
29.92, 14.7 psi |
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What are the 2 temperature scales that are commonly used? |
Celsius and Fahrenheit |
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If 2 aircraft are flying with the same horsepower but at different altitudes why does the aircraft flying at a higher altitude fly faster? |
Because the air is not as dense |
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What is the term for the curve of the surface of an airfoil from the leading edge to the trailing edge? |
Camber |
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What aerodynamic forces affect aircraft in flight? |
1) Thrust 2) weight 3) Drag 4) Lift |
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How does drag act in relation to relative wind? |
Parallel |
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Define AOA |
The angle between an airfoil wing mean chord line and the aircraft flight path |
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How are airframe components joined? |
Rivets, bolts, screws, adhesive, welds |
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What are the 5 stresses to which airframe are subjected? |
1) Compression 2) Torsion 3) Tension 4) Shear 5) Bending |
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Which fuselage design does not use formers frame assemblies or bulkheads to give shape to the fuselage? |
Monocoque |
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What internal wing components serve as an attachment point for the skin? |
Ribs and stringers |
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What type of material is usually used for construction of flight control surfaces? |
Aluminum alloy |
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What is used to round out the angle formed between the fixed tail surfaces and the fuselage? |
A fairing |
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What structural unit provides a smooth airflow around and into the engine inlet? |
Engine nacelles |
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What component controls airflow around the weapons to reduce turbulence in the bay on some bomber aircraft? |
Spoilers |
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How do doors differ from panels |
Doors are hinged |
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Most transparent structures on an aircraft are made of what 2 materials? |
Transparent plastics or safety glass |
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How do paint removers and stripping compounds affect the plastic facings of a radome? |
It may adversely affect it's electrical properties or strength |
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How are fuselage station numbers measured? |
In inches from a reference datum |
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What are the 3 axis that an aircraft operates around? |
1) Longitudinal 2) Lateral 3) Vertical |
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What are the Lateral control surfaces of the aircraft? |
Ailerons spoilers/speed breaks and wing flaps |
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What controls all directional movements of the aircraft |
Primary flight controls |
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What primary flight control guides the aircraft about the vertical access? |
Rudder |
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Which type of stabilator has both sides connected together so that when one side moves the other side must move-in the same direction and amount |
Solid type |
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What is an elevon? |
A combo of the elevator and aileron |
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What are the 5 types of wing flaps |
1) Fowler 2) Plain 3) split 4) Slotted 5) Leading edge slats and flaps |
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What is the difference between leading edge flaps and wing slats |
Wing slats are independent systems from the flaps. leading edge flaps are in the same system as flaps |
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What is the purpose of speed breaks |
To create more drag to brake more efficently |
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List the three types of trim systems |
1) Roll 2) Pitch 3) Yaw |
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Which type of flight control system reduces the need for long cables turnbuckles quick disconnects push pull rods and the associated flight control hardware |
Fly by wire |
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What are the 2 major parts of the AFCS |
1) Auto pilot 2) Stability augmentation system |
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What autopilot system mode automatically maintains aircraft speed |
Mach hold |
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Define electricity |
A physical phenomena arising from the existence and interaction of electric charges |
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What particles are atoms composed of |
Protons neutrons electron |
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List 4 insulators |
Wood rubber plastic glass |
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List 4 conductors |
Platinum gold copper silver |
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Where do you normally use semiconductors |
In Solid state devices |
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What is emf |
Electromagnetic force |
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Define electrical current |
The movement of electrons through a conductor |
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What factors affecting the amount of resistance in a conductor |
Temperature type of conductor size |
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What unit of measurement is used to express electrical power |
Watts |
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What is the definition of magnetism |
The ability of a substance to attract |
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How are artificial magnets classified |
Permanent or temporary |
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What is permeability |
The ease of ability to conduct magnetic lines of force |
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What is residual magnetism |
The amount of magnetism that remains in a temporary magnet |
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How is magnetism induced in magnetic material |
Put it in a magnetic field or into contact with another magnet |
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Can magnetic lines of force be insulated? |
No |
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What are the 3 most commonly used shape of magnets? |
Bar ring and horseshoe |
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How can a magnet be weakened |
Heating or excessive jarring |
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Define flux |
A term for magnetic lines of force |
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How Is electromagnetism developed |
By current of electricity |
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When current flows through a conductor does a magnetic field exist |
Yes |
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What must you know to apply the left hand rule |
The direction of current flow |
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What rule do you use to determine the flux direction of a wire in a loop |
The left hand rule |
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How can an electromagnetic field strength be increased |
By using a few turns of a wire carrying a larger current or using many turns of wire carrying a small current |
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What is the purpose of a conductor |
Provide a path for electrons to flow with minimum resistance |
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Why are protective devices installed in aircraft electrical systems |
Protect against system overloads and shorts in a circuit |
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How much time must pass before resetting a trip free type circuit breaker? |
1 minute |
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What is the purpose of a current limiter |
To provide protection against fault circuits on power distribution circuits |
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What is the purpose of a resistor |
To control the amount of current flow in a circuit |
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Why is alternating current used as the primary electrical power source in aircraft |
Less power lost during transmission and the elimination of insulation and brushes |
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What is the unit of measurement for frequency |
Hertz |
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Define phase relationship |
A condition in which 2 moving objects are changing in or out of step |
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What are the 2 classifications of AC generation systems |
Variable frequency and constant frequency |
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What frequency is used for AC power generation on aircraft |
400hz |
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How is voltage induced in a brush type generator |
DC from an integral exciter generator is passed through windings on the rotor |
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How is voltage induced in a brush type generator |
A permanent magnet generator an ac exciter generator and the main AC generator |
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What weak point was eliminated by the design of a brushless type generator |
Arcing |
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What 3 components make up the stator |
PMG armature, exciter field and main armature windings |
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What are the 2 main components of an AC generator |
Rotor assembly and stator |
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What are the 2 functions of the CSD governor |
To control the drive output speed and equalize the load between generators operating in parallel |
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If CSD output rotation drives the generator below 365 hz, what component removes the generator from the bus |
Underspeed switch |
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If the CSD temp rises to an overheat condition what should be done to prevent further damage |
Disconnect the CSD |
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What is installed on most IDGs to provide for easier installation and removal |
A quick attach-detach clamp |
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How is voltage regulation and current limiting accomplished in the GCU |
By varying the generator excitation field |
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How does the frequency and load controller for each generator system regulate the frequency of the generator CSD |
By controlling the magnetic trim head governor on the CSD |
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What are the internal components of a battery |
Plates, separators, and electrolyte |
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What are the primary causes of premature failures of a lead acid battery |
Abuse, overcharge, low solution, under charge, and mountings |
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What is the fundamental unit of the nickel cadmium battery |
The cell |
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When does a nickel cadmium battery's electrolyte reach its max level |
When the battery is fully charged |
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How are nickel cadmium cells constructed |
By inserting positive and negative plates in plastic cases with nylon and cellophane separators |
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How are motors classified |
By voltage, current used, and methods of motor excitation |
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How can the direction of rotation for a series motor be changed |
By reversing the current flow in a field winding or reversing current flow in the armature |
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What advantage does the series motor have over other types of motors |
It operates on ac or DC excitation |
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How is the field winding of a shunt type motor connected with the armature |
In parallel |
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What type of TR is used to charge a nickel cadmium battery |
Charging TR |
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What is another name for a TR |
Converter |
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Define matter |
Any substance that has mass and takes up space |
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Since liquids and gases have many properties in common how are they frequently classified |
As fluids |
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All matter is made up of what |
Molecules |
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Which matter has the property of resisting changes in shape when a force is applied |
Solids |
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Which factors affect the amount of expansion and contraction of an solid |
The amount of temperature change and the expansion characteristics of the solid |
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For a liquid to transmit a pushing force what condition must exist first |
It must be completely enclosed in a container |
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What would cause a cylinder of air to increase pressure when placed in the sun |
The air expands and pressure increases |
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What is the main difference in the characteristics of gases compared to liquids |
Gases are compressible liquid is not |
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State the basic principle of pascals law |
When fluid is confined and force is applied the force is transmitted equally to all points in the system |
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Under what conditions does pascals law not apply to fluids |
Pascals law does not apply to fluids in motion |
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State the basic principle of Boyles law |
If pressure on a confined gas varies, its volume will vary inversely in the same proportion as long as the temperature does not change |
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What is another name for Boyles-charles law |
General gas law |
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What effect does an orfice have on fluid flow when compared to a venturi |
An orfice will cause more turbulence and more energy loss than a venturi because it is not streamlined |
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How can resistance to flow be reduced |
By streaming the flow |
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What pressure difference can be observed during fluid flow through a venturi |
A pressure drop at the narrow opening of a venturi as the rate of flow of the fluid increases at this point. The pressure increases again after passing through the throat |
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How much fluid should a reservoir hold |
Enough fluid to supply the normal operating needs of the system along with an additional amount to replace fluid lost through minor leakage |
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Why do nonpressurized reservoirs have space above the fluid |
To allow the fluid to purge its self of air bubbles that are picked up from the system |
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What prevents foreign material from entering the reservoir during servicing |
A wire screen |
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What are the two main reasons for pressurizing a reservoir |
To stop the fluid from foaming at high altitudes Ensure a positive supply of fluid to the pumps |
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How do you service a pressurized hydro reservoir with fluid |
Use a portable servicing cart |
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What unit in the pressurized hydro reservoir pressurizes the hydro fluid to 5 psi |
A piston spring |
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To service or perform maintenance on an air pressurized reservoir what is the first thing you must do |
Depressurize the reservoir |
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Name 3 functions of the air pressurized reservoir pressure regulator |
Regulates pressure to the reservoir Acts as a relief valve and has a differential valve to allow equalization of pressure between outside air and air inside the reservoir
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How are pumps classified |
By their displacement volume |
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What 2 purposes does a hand pump serve |
Emergency source of pressure And an auxiliary source of pressure for ground checking the operation of the system units |
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When the hand pump handle is on the retraction stroke which check valve is closed |
The inlet check valve |
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What indicates that either check valve inside the hand pump has malfunctioned |
The hand pump will become completely inoperative |
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If a third check valve is installed, what could be the problem if fluid is only sent into the system on the extension stroke |
The inlet check valve is malfunctioning |
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What is the drawback of a constant volume pump |
As long as the hand pump rotates the fluid flow it produces will eventually build up pressure high enough in the confined area to burst the lines and container |
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What is the thinned portion on the drive shafts of a gear type pump called |
Shear section |
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On a vane type pump what drives the cylinder block |
Springs |
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In the constant volume piston pump what drives the cylinder block |
Universal link |
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Why does a constant volume pump always have a constant intake and output of fluid |
There are always pistons somewhere between the upper and lower position |
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What does the suction boost pump do for engine driven pumps |
Ensures the engine pumps get an adequate supply fluid |
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What regulates pressure in a variable volume pump |
An integral flow control valve |
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What is the main difference between a vickers stroke reduction pump and a constant volume pump |
The angle between drive shaft and the cylinder block |
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What position is the vickers pumps cylinder block and yoke in when the system is at 0 psi |
The extreme angle position full flow |
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Do the pistons have a stroke when the vickers pumps reaches the zero flow point |
No |
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What are the two major component groups of Kellogg pump |
The rotating group and Pressure compensating group |
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What determines the length of the Kellogg pumps piston stroke |
The angle setting of the cam plate |
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What is the purpose of the creep plates in stratopower pumps |
Cooler operation |
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Describe the pistons of stratopower pump |
The pistons have fairly large hollow centers connected with cross drilled holes |
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Which way would you turn the adjusting screw on the stratopower pump to increase pressure |
Clockwise |
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What is the purpose of a hydraulic motor |
To convert hydraulic pressure into rotary mechanical motion |
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What is the purpose of an accumulator in a hydraulic system |
To store a volume of fluid under pressure, provide space for thermal expansion, and act as a cushion against pressure surges |
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What is the most common type of accumulator used |
Cylindrical type |
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Which accumulator has a drilled passageway in the piston for lubrication |
Piston accumulator |
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Where is the air servicing valve located on the piston accumulator |
At the bottom of the accumulator |
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What is the piston accumulator serviced with |
Dry air or nitrogen |
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Which accumulator has four separate chambers? |
Self displacing accumulator |
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What is the only moving part of a self displacing accumulator |
The piston |
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In the self displacing accumulator system where is the relief valve located |
Between the pressure and return lines |
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What are the 3 basic parts of a filler assembly |
Head, element, and bowl |
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Which part of the filler assembly is mounted to the aircraft |
The head |
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What does the micron rating mean |
The amount of dirt or contaminates that can be filtered out |
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What are the 2 ways fluids can usually flow through a filter assembly |
Normal flow and Bypass flow |
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How are the hydraulic manifolds designed |
To conserve space in the aircraft and ease of removing and replacing components |
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Why is it physically impossible to install the wrong valve in a manifold |
Alignment pins make it physically impossible to install the wrong valve |
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What is the purpose of an actuating cylinder |
To transform fluid flow into a mechanical force |
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What does tandem mean |
One behind the other |
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How many pistons are in the tandem actuator |
2 |
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What is the purpose of the internal snubber actuator |
To reduce damage to mechanisms by preventing the actuator from slamming into its end of travel with great force |
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Where is the main system relief valve normally installed in a hydraulic system |
Between the pressure and return lines |
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What is the purpose of a selector valve |
To control and direct the flow of hydraulic fluid |
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What is the advantage of a slide selector valve over the poppet type |
It's ability to meter fluid |
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What is the purpose of a check valve |
To allow free flow in one direction and no flow in the other |
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What are the different types of automatic check valves |
Ball Cone Flapper |
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Which type of check valve is used primarily in low pressure systems |
Flapper |
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What order of events do sequence valves set |
Branches of hydraulic circuit |